Merge topic 'policy-refactor'

8329fc01 cmPolicies: Replace unused include.
5447ca1a cmMakefile: Remove CMP0001 handling to callers.
d0dcce15 cmMakefile: Simplify computation of ancient policy status.
658bfc5c cmMakefile: Remove redundant condition from policy status computation.
f4a25874 cmMakefile: Inline internal policy status method.
3c45471c cmPolicies: Enable RVO for internal method.
71e69fc9 cmPolicies: Store only state that users can set.
84e18056 cmMakefile: Convert recursion to loop.

1 files changed, 16 insertions, 0 deletions

diff --git a/Source/cmCMakePolicyCommand.cxx b/Source/cmCMakePolicyCommand.cxx
index 3c878bf..3ef6d35 100644
--- a/Source/cmCMakePolicyCommand.cxx
+++ b/Source/cmCMakePolicyCommand.cxx
@@ -93,6 +93,22 @@ bool cmCMakePolicyCommand::HandleSetMode(std::vector<std::string> const& args)
     this->SetError("SET failed to set policy.");
     return false;
     }
+  if(args[1] == "CMP0001" &&
+     (status == cmPolicies::WARN || status == cmPolicies::OLD))
+    {
+    if(!(this->Makefile->GetState()
+         ->GetInitializedCacheValue("CMAKE_BACKWARDS_COMPATIBILITY")))
+      {
+      // Set it to 2.4 because that is the last version where the
+      // variable had meaning.
+      this->Makefile->AddCacheDefinition
+        ("CMAKE_BACKWARDS_COMPATIBILITY", "2.4",
+         "For backwards compatibility, what version of CMake "
+         "commands and "
+         "syntax should this version of CMake try to support.",
+         cmState::STRING);
+      }
+    }
   return true;
 }